1. Field of the Invention
The invention relates to a solar cell module including back junction solar cell.
2. Description of Related Art
A solar cell is considered as a new prospective source of energy because it can convert clean and inexhaustible supply of sunlight directly into electricity. Each solar cell can often produce only about a few watts of power. Hence, a solar cell module is used when solar cells are utilized to supply electrical power (energy source) to residential homes or buildings. A solar cell module is created by connecting individual solar cells electrically in order to increase electrical power output.
Here, Japanese Patent Laid-Open No. 2005-11869 discloses and brings forward a type of so-called back junction solar cell. Aiming to expand light-receiving dimensions, it has a plurality of n-doped regions and a plurality of p-doped regions on the back side of a semiconductor substrate arranged in stripe configuration. An n-type side thin wire electrode is formed on each n-doped region, and a p-type side thin wire electrode is formed on each p-doped region. Each n-type side thin wire electrode is connected to an n-type side connecting electrode formed on one side of the edge on the rear surface, and each p-type side thin wire electrode is connected to a p-type side connecting electrode formed on one side of the edge on the rear surface. By connecting n-type side connecting electrode of one solar cell and p-type side connecting electrode of another solar cell adjacent to the above-mentioned one solar cell by wiring member, one solar cell and another solar cell are connected electrically.
However, in the region of the back side of semiconductor substrate, wherein n-type side connecting electrode and p-type side connecting electrode are arranged, low collection efficiency of photogenerated carriers (electron or positive hole) has been a problem.